This review focuses on various side chain groups based on PDAs published over the last 3 years, covering urea, melamine, ferriferous oxide and coumarin. Perspectives on the remaining challenges and future developments are also proposed.

Organic compounds that contain nitrogen are very important intermediates in pharmaceutical and chemical industry. Hydroamination is the reaction that can form C–N bond with high atom economy. The research progress in metals catalyzed hydroamination of alkenes and alkynes from the perspective of reaction mechanism is categorized and summarized.

Advances in transition-metal (Ru, Co, Cu, and Fe) complex-based catalysts since 2000 are briefly summarized in terms of catalyst selection and application for photocatalytic H ₂ evolution.

A series of novel heterocyclic polymers with fluorescent brightening properties are synthesized via Click polymerization. Fast synthesis of poly-1,2,3-triazoles (M_n ≥ 9.31 kDa) is described herein, with a high yield of up to 95%. The Click polymerization approach has a number of advantages, including facile operation and outstanding isolation yield. The resultant polymers have a high thermal stability, excellent UV resistance, as well as acid and light fastness. On embedding with optical brightening agents, the polymers display strong fluorescent brightening properties in the tetrahydrofuran solution. Moreover, these products have a strong solution emission intensity and extraordinary photostability under UV light.

Light-emitting electrochemical cell of bithiazole-based material was fabricated by solution processing rendered high external quantum efficiency over 12.8% and luminance of 1.8 10 ⁴ cd m ^−2.

Polymers 4 containing poly(arylene ethynylene) were synthesized and characterized systematically. Among them, 4c exhibited a remarkable H₂ evolution rate (14.32 mmol h^–1 g^–1) with visible-light irradiation, lasting 72 h in different water qualities; the corresponding apparent quantum yield was 11.6% at 450 nm.